Abstract: A variable valve control apparatus includes an oscillating arm and a pivot lever pivotably mounted to each other via a swivel joint. A first roller, which is rotatably mounted on an arm of the pivot lever engages with the camming surface of a cam, while a second roller which is rotatably mounted on another arm of the pivot lever makes contact with a contact surface of an arcuate sliding block disposed within a housing of the valve control apparatus. The contact surface of the sliding block includes a first region which has an arcuate contour, and a radius that is centered on a pivot axis of the swivel joint when the valve is in the closed position, as well as a second region which adjoins the first region and has a curved spur that extends inwardly toward the swivel joint.

Abstract: A method for treatment of metallurgical wastes i.e. slags, which are in liquid form by introducing water into the liquid slag thus causing it to cool at a slow rate so that the solidified slag contains a porous crystalline or utrified strucutre according to the rate of cooling, which structure is stable at ambient temperature. Another object of the invention concerns an apparatus for treating solid metallurgical slags, comprising a continuous conveyor formed of moulds and means adapted to diffuse water into the liquid slag.

Abstract: Fume dust is prevented when molten metal is poured into a vessel, and water or water mist is sprayed into the vessel or onto the molten metal, creating a reduced level of oxygen concentration of about 12% by volume, preferably about 8% by volume, inside the vessel or at the molten metal surface.

Abstract: A system and method for delivering a gas-supersaturated fluid comprising a fluid reservoir, a fluid pump, a gas source, a high pressure gas exchanger, and one or more arrays of capillary channels is disclosed. Suitable controls such as differential pressure gauge and valves are provided to maintain a near constant hydrostatic pressure of the fluid within the semi-permeable membrane gas-fluid interface of the gas exchanger at approximately 1% to 20% higher than the gas partial pressure of the fluid within the gas exchanger. Gas-supersaturated fluid output from the gas exchanger via the capillary channels is at a flow velocity of greater than 0.05 m/sec, thereby facilitating delivery of large flow rates of gas-supersaturated fluids without cavitation inception.

Abstract: A method of injecting gas-supersaturated fluids as a bubble-free effluent from a delivery system into a relatively low pressure, gas-depleted environment without cavitation or bubble formation. The method includes the steps of eliminating cavitation nuclei from within the delivery system, compressing a fluid and a gas at a high partial pressure to form a gas-supersaturated fluid, and ejecting the gas-supersaturated fluid through the delivery system into the environment without associated cavitation formation in the effluent.

Abstract: During melting in an electric melting furnace of iron products such as pig iron, scrap iron, directly reduced iron pellets, and various alloy metals, or mixtures of the foregoing having greatly varying impurities, solid carbon dioxide is led over the melting hearth shortly before, during, and after charging. Explosive burning of the combustible constituents is thus prevented in that the oxygen is displaced during the charging operation by the expanding gaseous carbon dioxide produced. The method makes possible electric steel production with reduced accumulation of dust and fumes in that formation thereof is largely eliminated directly at the source. By cutting down on the high volumes of gas and gas temperatures occurring during charging without carbon dioxide, substantially smaller filter installations are needed, whereby the amount of savings on investment and operating costs economically compensates for the cost of the carbon dioxide utilization.

Abstract: The present invention pertains to a gas purging plug with integrated electrode for use in electric-arc furnaces.

Abstract: In a method for decarburizing metals and alloys, a two-gas component mixture consisting only of oxygen and carbon dioxide is introduced into molten metals or alloys at least during the first decarburization phase.